Silica-coated deposit layer formed by plating

ABSTRACT

Improved plating is provided. The present invention provides a plated product which comprises a base, a deposit layer formed by plating on a surface of the base, and a silica-compound-containing coating layer formed on the surface of the deposit layer. The coating layer has a thickness of 0.1-100 μm, preferably 0.1-20 μm, more preferably 0.1-10 μm, even more preferably 0.1-5 μm. The coating layer may contain a dye and/or a pigment.

TECHNICAL FIELD

The present invention is related to a silica-coated plating layer,especially directed to a product having a silica-coated plating layer,and provides a preparation method thereof.

BACKGROUND ART

In order to lighten an interior part and an exterior part of anautomobile, a part formed with a resin such as an ABS resin or polyamideresin is used. In addition, in order to impart luxurious feel andaesthetic to the part, plating is applied to the surface thereof.

For example, Japanese Laid-Open Publication No. 2005-231219 (PatentLiterature 1) discloses a plated resin mold body for an automobile partthat has a metal plating layer at the surface of a thermoplastic resinmold body. In addition, Japanese Laid-Open Publication No. 2002-241948(Patent Literature 2) discloses plated members made of a synthetic resinfor vehicles such as a lock release lever and an operation knob of anautomobile.

Regarding the plating layer on the surface of these members, in order tomaintain beauty in the appearance thereof, for example, JapaneseLaid-Open Publication No. 2015-221528 (Patent Literature 3) suggests thetechnique of imparting resistance against stain due to a fingerprint(hereinafter, referred to as “fingerprint resistance”) by applyingfluorine coating with water repellency and oil repellency to the platedsurface. In addition, as another method for maintaining beauty in theappearance, prevention of physicochemical change and/or damage in aplating layer is also required.

Furthermore, although a plating layer on a surface exhibits an aestheticby itself, because of the custom-made orientation of recent years, it isrequired to make fine adjustments of texture and color tone withoutimpairing the aesthetic of the plating layer itself.

CITATION LIST Patent Literature

[PTL 1] Japanese Laid-Open Publication No. 2005-231219

[PTL 2] Japanese Laid-Open Publication No. 2002-241948

[PTL 3] Japanese Laid-Open Publication No. 2015-221528

SUMMARY OF INVENTION Solution to Problem

The inventors discovered that improvement in various characteristicsincluding improvement in fingerprint resistance, enhancement ofresistance against physicochemical change and/or damage can be obtainedby applying silica-coating to a plating layer (for example, platinglayer on a substrate), and discovered that this silica-coating has highstability by strongly adhering with a plating layer. Furthermore, it wasdiscovered that silica-coating is very preferable for adjusting thecolor tone of a plating layer.

Based on these findings, the present invention provides a silica-coatedplating layer (for example, plating layer on a substrate) and themanufacturing method thereof.

Therefore, the present invention provides the following items.

(Item A1)

A plated product comprising:

a substrate made of resin;

a plating layer formed on a surface of the substrate; and

a coating layer comprising a silica compound, which is formed on asurface of the plating layer.

(Item A2)

The plated product of item A1, wherein a thickness of the coating layeris 0.1 to 20 μm.

(Item A3)

The plated product of item A1, wherein a thickness of the coating layeris 0.1 to 10 μm.

(Item A4)

The plated product of item A1, wherein a thickness of the coating layeris 0.1 to 5 μm.

(Item A5)

The plated product of any one of items A1 to A4, wherein the coatinglayer comprises at least one of a dye and a pigment.

(Item A6)

The plated product of any one of items A1 to A5, wherein the coatinglayer comprises an added resin.

(Item A7)

The plated product of any one of items A1 to A6, which is for a vehicle.

(Item A8)

A method of manufacturing a plated product comprising:

a step of forming a plating layer on a surface of a substrate made ofresin; and

a step of applying a coating agent comprising a silica compound to asurface of the plating layer to form a coating layer.

(Item A9)

A method of manufacturing of item A8, comprising a step of carrying outplasma treatment, acid treatment, or alkali treatment to a formedplating layer before the step of forming a coating layer.

(Item A10)

The method of manufacturing of item A8 or A9, wherein a thickness of thecoating layer is 0.1 to 20 μm.

(Item A11)

The method of manufacturing of item A8 or A9, wherein a thickness of thecoating layer is 0.1 to 10 μm.

(Item A12)

The method of manufacturing of item A8 or A9, wherein a thickness of thecoating layer is 0.1 to 5 μm.

(Item A13)

The method of manufacturing of any one of items A8 to A12, wherein thecoating agent comprises an added resin.

(Item A14)

The method of manufacturing of any one of items A8 to A13, wherein theproduct is a product for a vehicle or an electronic product for ahousehold.

(Item 1)

A plated product comprising:

a substrate made of resin;

a plating layer formed on a surface of the substrate; and

a coating layer comprising a silica compound, which is formed on asurface of the plating layer.

(Item 2)

The plated product of item 1, wherein a thickness of the coating layeris 0.1 to 20 μm.

(Item 3)

The plated product of item 1, wherein a thickness of the coating layeris 0.1 to 10 μm.

(Item 4)

The plated product of item 1, wherein a thickness of the coating layeris 0.1 to 5 μm.

(Item 5)

The plated product of any one of items 1 to 4, wherein the coating layercomprises at least one of a dye and a pigment.

(Item 6)

The plated product of any one of items 1 to 5, wherein the coating layercomprises an added resin.

(Item 7)

The plated product of any one of items 1 to 6, which is for a vehicle.

(Item 8)

A method of manufacturing a plated product comprising:

a step of forming a plating layer on a surface of a substrate made ofresin; and

a step of applying a coating agent comprising a silica compound to asurface of the plating layer to form a coating layer.

(Item 9)

A method of manufacturing of item 8, comprising a step of carrying outacid or alkali treatment to a formed plating layer before the step offorming a coating layer.

(Item 10)

The method of manufacturing of item 8 or 9, wherein a thickness of thecoating layer is 1 to 20 μm.

(Item 11)

The method of manufacturing of item 8 or 9, wherein a thickness of thecoating layer is 1 to 10 μm.

(Item 12)

The method of manufacturing of item 8 or 9, wherein a thickness of thecoating layer is 3 to 5 μm.

(Item 13)

The method of manufacturing of any one of items 8 to 12, wherein thecoating agent comprises an added resin.

(Item 14)

The method of manufacturing of any one of items 8 to 13, wherein theproduct is a product for a vehicle.

The present invention is intended so that one or more of theaforementioned features can be provided not only as the explicitlydisclosed combinations, but also as other combinations thereof.Additional embodiments and advantages of the present invention arerecognized by those skilled in the art by reading and understanding thefollowing detailed descriptions, as needed.

Advantageous Effects of Invention

According to the present invention, it is possible to obtain a platedproduct having excellent electrical resistance/insulation, excellentfingerprint resistance, resistance against physicochemical change and/ordamage and/or corrosion resistance without impairing the metal textureby applying silica-coating to the surface of a plating layer (forexample, plating layer on a substrate). In addition, according to thepresent invention, the appearance (especially texture and color tone) ofa plated product can be finely adjusted by silica-coating. Thecharacteristic of being able to finely adjust the appearance may beespecially useful in a part for an automobile or the like that requiresa small adjustment in design.

DESCRIPTION OF EMBODIMENTS

The present invention is explained below while showing the bestembodiment. It should be understood that the terms used in the presentspecification are used in the meanings that are generally used in thesubject field unless specifically referred to. Therefore, unless definedotherwise, all technical terms and scientifically technical terms usedin the present specification have the same meaning as the termsgenerally understood by those skilled in the art of the field to whichthe present invention belongs. When there is contradiction, the presentspecification (including definition) is prioritized.

The details of the present invention are explained below.

The present invention relates to a plating layer on whose surface asilica-coating layer is formed. Herein, the plating layer is formed on asubstrate such as a resin.

(Substrate)

The silica-coating plating of the present invention is applied on asubstrate. The substrate can be a substrate of any material such as asubstrate made of metal or a substrate made of glass, and the substrateis preferably made of resin, or a portion made of resin in the article.A substrate made of resin may be a substrate manufactured with any kindof resin as long as the resin is a resin having the characteristics ofstrength, impact resistance and that like that are necessary for theusage of the substrate. The present specification calls a resin used ina substrate on which silica-coating plating is to be or has been applieda “resin for a substrate”. A resin for a substrate includes, forexample, but not limited to, AS resin, ABS resin, acrylic resin,polycarbonate resin, polyethylene terephthalate resin, polybutyreneterephthalate resin, polypropylene resin, polyamide resin, polymethylmethacrylate resin, polyallyl diglycol carbonate resin. Any suitableresin used in the subject technical field can be used. Among the above,ABS resin, polycarbonate resin, polyamide resin, or the like ispreferable. Typically, the substrate made of resin of the presentinvention can be a mold article injection molded from these resins. Asubstrate manufactured with these resins is generally softer than asubstrate made of metal and is easy to be degenerated/deformed. Asubstrate may be transparent or opaque, and may be colored or notcolored.

The substrate in the present invention may be an integrally moldedsubstrate, or may be a substrate consisting of two or more differentmembers by two-color molding or the like. For example, when a membraneconsists of two or more different members, the substrate may consist ofa plated member and an unplated member, and may consist of a transparentmember and an opaque member, or a transparent member and a coloredmember.

The present invention can arbitrarily change the roughness (arithmeticaverage surface roughness) of a substrate surface in accordance with theusage and design of a product. For example, when brightness is needed tobe reduced without imparting gloss to the surface of a product, thedegree of unevenness of the surface of a substrate is made larger, whileon the other hand, when gloss is imparted to the surface of a product,the degree of unevenness of the substrate surface is made smaller.

Although arithmetic average surface roughness may arbitrarily change inaccordance with the usage and design of a product, the arithmeticaverage surface roughness of a substrate is generally 0.03 to 1.0 μm.When expression of gloss in a product surface is intended, thearithmetic average surface roughness of a substrate will be smaller, andwhen pearskin (matte) is attempted to be expressed in a product surface,the arithmetic average surface roughness of a substrate will be larger.Arithmetic average surface roughness can be measured using a stylus typesurface roughness meter.

(Plating Layer)

A plating layer is formed on a surface of the above-described substrate.A plating layer may be formed by a conventional method. A plating layermay be formed throughout a substrate, or may be formed on one portion.Different plating layers may be formed for each portion of a substrate,or the same plating layer may be formed. A plating layer may be aplating layer of various metal types, or may be made of an alloy. Themetal type that can be used in the plating layer of the presentinvention includes, but not limited to, aluminum (Al), magnesium (Mg),cobalt (Co), nickel (Ni), chrome (Cr), copper (Cu), silver (Ag), tin(Sn), zinc (Zn), iron (Fe), gold (Au) and the like, or may be an alloyof any of these metal types. A plating layer or a portion of a platinglayer may be a single layer, or a plurality of layers. When a platinglayer or a portion of a plating layer is configured from a plurality oflayers, a metal configuring the layers may be different for every layer,or the same.

In one embodiment, a plating layer can be a single layer. In oneembodiment, a plating layer can consist of two layers, which are a baselayer and an outer layer. In one embodiment, a plating layer can consistof three layers, which are a base layer, an intermediate layer and anouter layer. In one embodiment, a plating layer can consist of four ormore layers. In one embodiment, the metal type of a base layer can becopper, nickel, or an alloy thereof. In one embodiment, the metal typeof an intermediate layer can be nickel, tin-nickel, tin-cobalt,tin-copper, or iron-nickel. In one embodiment, the metal type of anouter layer can be chrome, zinc, gold, copper, tin-cobalt, tin-nickel,gold-copper, or any alloy thereof. In one embodiment, another processingsuch as antique-like plating may be practiced after plating.

The color of an outermost layer of a plating layer would be the color ofthe plating layer in a product. For example, the color of a chromeplating is normally silver color. Although black color chrome plating isalso possible, black color chrome plating is relatively low instability.

The silver color of chrome plating has a luxurious feel and isdecoratively preferable.

The membrane thickness of each layer of a plating layer can bearbitrarily set in accordance with the usage or the like of the product.

For example, the membrane thickness of a base plating layer can be 5 to50 μm, preferably 15 to 40 μm. The thickness of a copper plating layeris normally 5 μm to 50 μm.

The membrane thickness of an intermediate plating layer is preferably 5to 50 μm, more preferably 5 to 20 μm.

The membrane thickness of a plating layer on the outer side ispreferably 0.05 to 3.0 μm. When a plating layer on the outer side isformed with a trivalent chrome, the membrane thickness thereof ispreferably 0.1 to 0.3 μm. When forming with a hexavalent chrome, themembrane thickness thereof is preferably 0.1 to 3.0 μm or 0.1 to 1.5 μm,and an especially preferable membrane thickness is 0.1 to 0.5 μm.

A plating layer is, for example, formed on a surface of a substratethrough the (a) electroless nickel plating step and the (b)electroplating step.

(a) Electroless Nickel Plating Step

First, a substrate is water washed and a metal plating layer is formedon the surface thereof by electroless nickel plating (chemical plating).Electroless plating can be carried out in the following manner.

Etching Step:

After immersing the substrate in an aqueous solution of chromicanhydride and sulfuric acid at a predetermined temperature, thesubstrate is water washed and the surface is roughened. Herein, thepredetermined temperature can be 60 to 75° C.

Catalyst (Catalyzer) Step:

After immersing the substrate in an aqueous solution of palladiumchloride, stannous chloride and hydrochloric acid, the substrate iswater washed and the substrate surface is caused to adsorb palladium.

Accelerator Step:

The substrate is immersed in an aqueous solution of hydrochloric acidand water washed and the tin adsorbed together with the palladium in thecatalyst step is dissolved/removed with hydrochloric acid.

(b) Electroplating Step

Next, electroplating can be carried out on an electroless plating layerin the following manner. As described below, after carrying out copperplating, nickel plating, chrome plating, or chrome alloy plating can becarried out.

First, a copper plating layer is formed on the surface of theelectroless plating layer by electroplating.

The copper plating conditions can be, for example, as described below.In a copper sulfate bath of copper sulfate with the concentration of 60to 250 g/l and sulfuric acid with the concentration of 80 to 200 g/l, apart is immersed at 10 to 30° C. and plating is carried out at thecathode current density of 0.5 to 5 A/dm².

Next, a nickel layer is formed on the surface of the copper platinglayer by electroplating. In other words, after immersing the part in amixed liquid comprising nickel sulfate, nickel chloride, boric acid,gloss agent, treatment is carried out with the cathode current densityof 0.5 to 5 A/dm² and then the part is water washed and a coat of nickelis formed on the surface of the part.

Next, a chrome layer or a chrome alloy layer is formed on the surface ofthe nickel layer by electroplating. The composition of a plating liquidcan use at least one of, for example, chromium sulfate (trivalent),chromium acetate (trivalent), chromium nitrate (trivalent), chromiumchloride (trivalent), chromium biphosphate (trivalent) and the like.

(Coating Layer)

A coating layer comprising a silica compound (also referred to as“silica-coating layer” in the present specification) is formed on thesurface of the plating layer described above by applying a coating agentcomprising the silica compound. A coating layer may be appliedthroughout a plating layer, or may be applied to only one portion. Acoating layer comprising a silica compound alone may be formed, oranother coating layer may be formed on a plating layer. Differentcoating layers may be formed for each portion of a plating layer. In apreferable embodiment, a coating layer is applied so as to form acontinuous film. In such an embodiment, it is possible to effectivelyprevent contact of a substance from outside to a layer (for example,plating layer) below a coating layer, wherein good corrosion resistancecan be achieved.

The thickness of a coating layer can be 0.01 to 100 μm or 0.05 to 100μm, preferably can be 0.05 μm to 20 μm, 0.05 to 15 μm, 0.1 μm to 20 μm,or 0.1 to 15 μm, more preferably 0.1 to 1.0 μm, further preferably canbe 0.1 to 5 μm. In one embodiment, the thickness of a coating layer canbe 1 to 20 μm, 1 to 15 μm, 1 to 10 μm, 2 to 7 μm, or 3 to 5 μm. Forexample, when a coating layer with the thickness of 5 μm is attempted tobe applied, although it depends on the article, there can be a casewherein there is variation of thickness of about ±2 μm, which variationcan affect the appearance of the article. Meanwhile, when a coatinglayer with the thickness of 0.5 μm or less is attempted to be applied,variation can be controlled to be less than ±2 μm and an excellentaesthetic can be achieved by retaining the uniformity of the appearance.In one embodiment, when the target thickness of a coating layer is thin(for example, about 0.1 μm), it may be possible to form a thin coatinglayer that is excellent in uniformity by having a very low viscosity ina coating agent. According to the present invention, a silica-coatinglayer is hard and thus sufficient resistance (protection effect) againstphysical change/damage (scratch, dent, or the like) can be obtained evenwhen the silica-coating layer is thin. In addition, a silica-coatinglayer can also have resistance (protection effect) against chemicalchange/damage such as rust, and can exhibit excellent electricalresistance/insulation.

A silica-coating layer itself can be transparent and it may be possibleto maintain the texture and/or color tone of a plating layer thereunder.

In one embodiment, a silica compound comprised in a coating agent is acompound represented by a general formula (I):

(R¹)_(m)Si(OR²)_(4-m)   (I)

<In the formula, R¹ represents a functional group or lower alkyl group,R² represents a lower alkyl group, each R¹ and each R² is independentlyselected, and m is an integral number of 0 to 3.>

In the above-described general formula (I), the functional grouprepresented by R² includes, for example, vinyl, ester (ester of loweralcohol and lower carboxylic acid, or the like), aromatic group such asphenyl, 3-glycidoxypropyl, 3-glycidoxypropylmethyl,2-(3,4-epoxycyclohexyl)ethyl, p-styryl, 3-methacryloxypropyl,3-methacryloxypropylmethyl, 3-acryloxypropyl, 3-aminopropyl,N-2-(aminoethyl)-3-aminopropyl, N-2-(aminoethyl)-3-aminopropylmethyl,3-triethoxysilyl-N-(1,3-dimethyl-butylidene)propylamine,N-phenyl-3-aminopropyl, N-(vinylbenzyl)-2-aminoethyl-3-aminopropyl,tris-(trimethoxysilylpropyl)isocyanurate, 3-ureidopropyl,3-mercaptopropyl, 3-mercaptopropylmethyl,bis(triethoxysilylpropyl)tetrasulphide, 3-isocyanatepropyl,3-propylsuccinic acid anhydride, and the like.

In the general formula (I) described above, the lower alkyl grouprepresented by R¹ or R² includes, for example, a linear, branched, orcyclic alkyl group with the carbon number of about 1 to 6 such asmethyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl,sec-butyl, n-pentyl, 1-ethylpropyl, isopentyl, neopentyl, hexyl, whereina part of these groups may be unsaturated.

Specific examples of silica compounds represented by the general formula(I) described above can include Si(OCH₃)₄, Si(OCH₂CH₃)₄, CH₃Si(OCH₃)₃,CH₃Si(OCH₂CH₃)₃, CH₃CH₂Si(OCH₃)₃, CH₃CH₂Si(OH₂CH₃)₃, CH₂CHSi(OCH₃)₃,CH₂CHOCH₂OCH₂CH₂CH₂Si(OCH₃)₃, CH₂C(CH₃)COOCH₂CH₂CH₂Si(OCH₃)₃,CH₂CHCOOCH₂CH₂CH₂Si(OCH₃)₃, NH₂CH₂CH₂CH₂Si(OCH₃)₃, HSCH₂CH₂CH₂Si(CH₃)₃,OCNCH₂CH₂CH₂Si(OCH₂CH₃)₃.

A coating agent may comprise an untreated silica compound, or maycomprise a silica compound that was hydrolyzed and polymerizedbeforehand. In the present specification, “silica compound” is used inthe meanings of both silica compound of a monomer and polymerized silicacompound. An alkoxysilane oligomer is formed by progression ofhydrolysis and polymerization reaction of a silica compound after usinga coating agent. In one embodiment, after applying a coating agent to aplating layer, the coating agent can be cured by the polymerizationreaction of a silica compound. Polymerization reaction of a silicacompound includes, for example, addition polymerization and dehydrationcondensation. In addition, condensation reaction between a silicacompound and a plating layer can progress in parallel with thepolymerization reaction between silica compounds. In a preferableembodiment, a silica compound can polymerize by dehydration condensationand bind with a plating layer via dehydration condensation reaction withan OH group on the plating layer.

The polymerization degree of a silica compound is not particularlylimited and can be a polymerization degree that does not inhibit itsapplication to a plating layer. For example, a silica compound of theweight average molecular weight of about 1000 to 10000 can be used butnot limited to this.

A coating agent preferably comprises a silica compound of 1 to 10 wt %.

A coating agent may comprise a solvent. It is possible to use anysuitable solvent that distributes the ingredient comprised in a coatingagent, and the solvent includes, for example, a solvent that isalcohol-based, glycol-based, glycol ether-based, ether-based, etheralcohol-based, ketone-based, hydrocarbon-based, ester-based, and thelike.

A coating agent may comprise one or more types of dye and/or pigment. Adye and/or pigment preferably does not impair the texture/fine sight ofa plating layer. A coating agent that comprises a dye and/or pigment canbe transparent. In one embodiment, a coating agent can have electricalresistance and/or insulation.

A dye and/or pigment includes, for example, but not limited to, salts(for example, sodium salt) of colorant acid comprising an acidic groupsuch as sulfone group or carboxyl group, which are, for example, acidiccolorants such as brilliant blue; dyes such as dyes that are azo-based,anthraquinone-based and indigo-based; organic pigments such as azolake,insoluble azo, condensed azo, quinacridone and phthalocyanine; andinorganic dyes such as titanium oxide, red iron oxide, red lead, chromeyellow, zinc yellow, ultramarine, dark blue, carbon black, graphite andiron oxide black. It is possible to use any suitable dye and/or pigmentused in the subject technical field.

The ratio of the dye and/or pigment in a coating agent can be 0.01 to 10wt %. Such content of dye and/or pigment enables supplemental coloringwithout impairing the texture/fine sight of a plating layer.

A coating agent may comprise an added resin. In the presentspecification, “added resin” refers to a resin that was added or is tobe added to a coating agent. An added resin can be, for example, thoseof materials including, but not limited to, acrylic, urethane, epoxy,polyester and melamine. In one preferable embodiment, an added resin isan acrylic resin. In one embodiment, an added resin comprises a core ofsaid materials and an alkoxysilyl group on the surface of the core. Inone embodiment, an alkoxysilyl group on the surface of a core isrepresented by:

Core-L-Si(R¹)_(m)(OR²)_(3-m)   (II)

<In the formula, R² represents a functional group or lower alkyl group,R² represents a lower alkyl group, each R² and each R² are independentlyselected, L is oxygen or absent, and m is an integral number of 0 to 3.>

In the above-described general formula (II), the functional grouprepresented by R² includes, for example, vinyl, ester (ester of loweralcohol and lower carboxylic acid, or the like), aromatic group such asphenyl, 3-glycidoxypropyl, 3-glycidoxypropylmethyl,2-(3,4-epoxycyclohexyl)ethyl, p-styryl, 3-methacryloxypropyl,3-methacryloxypropylmethyl, 3-acryloxypropyl, 3-aminopropyl,N-2-(aminoethyl)-3-aminopropyl, N-2-(aminoethyl)-3-aminopropylmethyl,3-triethoxysilyl-N-(1,3-dimethyl-butylidene)propylamine,N-phenyl-3-aminopropyl, N-(vinylbenzyl)-2-aminoethyl-3-aminopropyl,tris-(trimethoxysilylpropyl)isocyanurate, 3-ureidopropyl,3-mercaptopropyl, 3-mercaptopropylmethyl,bis(triethoxysilylpropyl)tetrasulphide, 3-isocyanatepropyl,3-propylsuccinic acid anhydride, and the like.

In the general formula (II) described above, the lower alkyl grouprepresented by R¹ or R² includes, for example, a linear or branchedalkyl group with the carbon number of about 1 to 6 such as methyl,ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, sec-butyl,n-pentyl, 1-ethylpropyl, isopentyl, neopentyl, hexyl.

In one embodiment, an alkoxysilyl group on the surface of a core is whatwherein said silica compound is polymerized to the alkoxysilyl group ofthe general formula (II) described above.

The ratio of an added resin in a coating agent can be 10 to 30 wt %. Acoating agent can bind to a plating layer even stronger by comprising anadded resin.

A coating agent may comprise water. The content of water is notspecifically limited, and can be about 1 to 10 wt % relative to thecoating agent.

A coating agent may comprise a catalyst component. Acid, base, organicmetal compound, or the like can be used as a catalyst component.

An acid includes, for example, inorganic acids such as hydrochloricacid, nitric acid, sulfuric acid, phosphoric acid and boric acid; andorganic acids such as formic acid, acetic acid, citric acid, oxalic acidand sulfonic acid.

A base includes, for example, hydroxides of an alkali metal or an alkaliearth metal such as potassium hydroxide and sodium hydroxide; and aminecompounds such as primary amine such as monomethylamine, secondary aminesuch as diethylamine, tertiary amine such as triethylamine, ammonia,pyridine, and pyrimidine.

An organic metal compound includes, for example, water-soluble organicmetal chelate compounds or metal alkoxides containing metal componentssuch as titanium, zirconium, aluminium, tin, and the like.

An organic metal chelate compound includes, for example, titaniumchelate compounds such as titanium diisopropoxy bisacetylacetonate,titanium tetra acetylacetonate, titanium dioctyloxybisethylacetoacetonate, titanium octylene glycolate, titanium diisopropoxybisethylacetylacetonate, titanium lactate, titanium lactate ammoniumsalt and titanium diisopropoxy bistriethanolaminate; zirconium chelatecompounds such as zirconium tetra acetylacetonate, zirconium tributoxymonoacetyl acetonate, zirconium dibutoxy bisethylacetoacetate andzirconium tributoxy monostearate; aluminum chelate compounds such asethylacetoacetate aluminum diisopropylate, aluminum tris ethyl acetate,alkyl acetoacetate aluminum diisopropylate and aluminummonoacetylacetonate bisethylacetoacetate; and the like.

A metal alkoxide includes, for example, titanium alkoxide compounds suchas tetraisopropyl titanate, tetranormalbutyl titanate, butyl titanatedimer, tetra tertiary butyl titanate and tetraoctyl titanate; zirconiumalkoxide compounds such as normal propyl zirconate and normal butylzirconate; aluminum alkoxide compounds such as aluminum isopropylate,monobutoxy aluminum diisopropylate and aluminum butyrate; and the like.

Regarding the above-described catalyst components, one type may be usedalone, or two types or more may be used in combination.

The content of a catalyst component is not specifically limited, and canbe about 0.01 to 20 wt %, preferably about 0.1 to 10 wt %, relative to acoating agent.

A coating agent may comprise colloidal silica. Colloidal silica is adispersion body wherein spherical silica particles or spherical silicaparticles in the form of chains are dispersed in a solvent. Colloidalsilica acts as a membrane formation assistant, which can enhance rustprevention ability of a silica coating by mixing it with a coatingagent.

Silica particles in colloidal silica may be a ultrafine particles in theorder of nanometer, which, for example, preferably has the averageparticle size of about 10 to 200 nm, more preferably about 10 to 100 nm.In addition, the particle size of silica particles can be measured bytransmission electron microscope (TEM) observation, a measurement methodusing a conversion value from a specific surface area measurement value(JIS 28830) by the BET absorption method, or the like, wherein anaverage particle size can be calculated by averaging the particle sizeof each particle.

In accordance with the type of the dispersion medium, colloidal silicais classified into water-based colloidal silica wherein water is thedispersion medium, and solvent-based colloidal silica wherein organicsolvent is the dispersion medium. Either colloidal silica may be used.

In accordance with the liquidity, water-based colloidal silica isclassified into alkaline type and acidic type, and either type may beused. Acidic type colloidal silica is preferable because the stabilityof a treatment liquid can be retained.

An organic solvent which is a dispersion medium of a solvent-basedcolloidal silica includes, for example, methanol, isopropanol,dimethylacetamide, ethylene glycol, ethylene glycol mono-n-propyl ether,ethylene glycol monoethyl ether, ethyl acetate, propyleneglycolmonoethyl ether acetate, methyl ethyl ketone, methyl isobutyl ketone,toluene, hexane, and the like.

The concentration of silica particles in colloidal silica is notspecifically limited, and can be, for example, about 5 to 40 wt %.

The mixing amount of colloidal silica in a coating agent can be mixed sothat the concentration of a solid content including a silica particlewould be about 1 to 50 wt %, preferably mixed so that the concentrationof a solid content including a silica particle would be about 1 to 30 wt%.

The total concentration of the silica compound and the silica particlesin a coating agent is preferably set to be about 0.1 to 50 wt %, morepreferably set to be about 5 to 40 wt %.

A coating agent may comprise a lubricant. A lubricant that can reducefriction coefficient of a coating layer to be formed can be used. Alubricant include, for example, solid lubricants such as metal dustssuch as silver, copper and lead, graphite, molybdenum disulfide, organicmolybdenum, and fine powder wax; semisolid lubricants such as grease;liquid lubricants such as silicone oil; and the like. Preferablelubricant is fine powder wax or silicone oil.

A fine powder wax can be a wax of fine powder having a particle sizethat is less than the membrane thickness of a siliceous film formed onthe surface of a treated object, wherein it is preferable that the finepowder wax is, for example, a fine powder wax that has the particle sizeof about 0.01 to 10 μm, for example, about 0.01 to 5 μm, about 0.01 to 1μm, about 0.01 to 0.1 μm, about 0.02 to 5 μm, about 0.02 to 1 μm, orabout 0.03 to 0.1 μm. Such fine powder wax includes, for example, amidewax, paraffin wax, carnauba wax, lanolin wax, polytetrafluoroethylenewax, polyethylene wax, polypropylene wax, and the like. The treatmentliquid of the present invention may comprise a mixture of two or moretypes of these fine powder waxes.

Silicone oil is a linear polymer comprising a siloxane bond, which isclassified into dimethyl silicone oil wherein the side chains andterminals are all methyl groups and modified dimethyl silicone oilwherein an organic group or hydrogen atom is introduced to a side chainor a terminal. Either type can be used as the dimethyl silicone oil thatis to be mixed in the coating agent of the present invention.

Furthermore, in accordance with the organic group or hydrogen atomintroduced to a side chain and/or terminal, modified dimethyl siliconeoil is classified into non-reactive modified dimethyl silicone oil andreactive modified dimethyl silicone oil. The dimethyl silicone oil thatis to be mixed in the coating agent of the present invention can be ofeither type, and from the viewpoint of forming a uniform coating agent,reactive modified dimethyl silicone oil is more preferable.

Non-reactive modified dimethyl silicone oil includes, for example,polyether modified dimethyl silicone oil, aralkyl modified dimethylsilicone oil, fluoroalkyl modified dimethyl silicone oil, long chainalkyl modified dimethyl silicone oil, higher fatty acid ester modifieddimethyl silicone oil, higher fatty acid amide modified dimethylsilicone oil, higher fatty acid modified dimethyl silicone oil, phenylmodified dimethyl silicone oil, polyether/methoxy modified dimethylsilicone oil, polyether/long chain alkyl/aralkyl modified dimethylsilicone oil, long chain alkyl/aralkyl modified dimethyl silicone oil,and the like.

Reactive modified dimethyl silicone oil includes, for example, aminomodified dimethyl silicone oil, monoamine modified dimethyl siliconeoil, diamine modified dimethyl silicone oil, epoxy modified dimethylsilicone oil, alicyclic epoxy modified dimethyl silicone oil, carbinolmodified dimethyl silicone oil, mercapto modified dimethyl silicone oil,carboxyl modified dimethyl silicone oil, hydrogen modified dimethylsilicone oil, amino/polyether modified dimethyl silicone oil,epoxy/polyether modified dimethyl silicone oil, epoxy/aralkyl modifieddimethyl silicone oil, methacryl modified dimethyl silicone oil, acrylicmodified dimethyl silicone oil, phenol modified dimethyl silicone oil,silanol modified dimethyl silicone oil, carboxylic acid anhydridemodified dimethyl silicone oil, diol modified dimethyl silicone oil, andthe like.

Normally, the mixing amount of a lubricant comprised in a coating agentcan be set to be about 0.01 to 30 wt %, preferably about 0.1 to 20 wt %,based on the total amount of a coating agent.

The mixing amount of a lubricant comprised in a coating agent may bedetermined in accordance with the total amount of solution comprising asilica compound and colloidal silica comprised in the coating agent. Forexample, a lubricant can be about 0.01 to 100 mass parts, preferablyabout 0.1 to 50 pass parts, with respect to 100 mass parts of a solutioncomprising a silica compound and colloidal silica.

In one embodiment, a coating agent comprising a silica compound, addedresin, organic metal compound and solvent can be suitably used. In oneembodiment, a coating agent further comprising dye and/or pigment can besuitably used. A combination of a silica compound, added resin, organicmetal compound and solvent that can be suitably used in such a coatingagent includes, for example, 10 wt % of silica compound, 20 wt % ofadded resin, 5 wt % of organic metal compound, and 65 wt % of solvent,wherein in one embodiment, the added resin is an acrylic resin.

In the present invention, the method for forming a coating layer on thesurface of a plating layer is not specifically limited, for example, acoating agent comprising a silica compound can be applied to the surfaceof a plating layer. A known method can be employed as the method forapplying a coating agent to the surface of a plating layer. For example,the spin coat printing method, dip coat method, silk printing method,pad printing method, spray coat method, roll coat method, and the likeare included.

In one embodiment, after carrying out plasma treatment, acid treatment,or alkali treatment to the surface of a plating layer, a coating agentis applied to the surface of the plating layer. By carrying out plasmatreatment, acid treatment, or alkali treatment, an OH group is formed ona plating layer surface of chrome, zinc or the like. An acid treatmentagent includes, for example, but not limited to, sulfuric acid, nitricacid, acetic acid, hydrofluoric acid, formic acid, oxalic acid, or acombination thereof, more specifically, DP-320 Clean, Topsun, or TopsunNF manufactured by OKUNO CHEMICAL INDUSTRIES, or the like, and an alkalitreatment agent includes, for example, but not limited to, ammonia,sodium hydroxide, potassium hydroxide, lithium hydroxide, and salt ofsodium, potassium, or lithium and weak acid, more specifically, AceClean 850, Ace Clean A-220 manufactured by OKUNO CHEMICAL INDUSTRIES, orthe like. A plasma treatment includes a method for directly irradiatingplasma discharge generated with a plasma discharge apparatus to thesurface of a plating layer.

After applying a coating agent to the surface of a plating layer, heattreatment may be carried out in order to firmly bind a coating layerwith the surface of a plating layer and speed up the curing of thecoating agent. The heat treatment temperature is determined whilstconsidering the heat resistant temperature of a substrate, and the heattreatment temperature can be 10 to 100° C. A polymerization method uponcuring a silica compound includes, for example, addition polymerizationand dehydration condensation, and a dehydration condensation-type silicacompound is generally cured at a temperature higher than an additionpolymerization-type silica compound. The use of a dehydrationcondensation-type silica compound is preferable in the presentinvention, and when a substrate is a resin, the temperature of heattreatment should be adjusted so as not to cause deformation/degenerationof the resin due to high temperature. In order to prevent degenerationof a substrate, the temperature of heat treatment can be less than 100°C. In one embodiment, curing treatment of a coating agent may be setbased on the target surface solidity of a coating layer. The time ofheat treatment can be about 30 seconds to 30 minutes. A device used uponcarrying out heat treatment is not specifically limited. Heat treatmentcan be carried out using a known device such as a drier or the like.

(Product)

The present invention provides a product wherein a plating layer isformed on a substrate and a silica coating is formed on the platinglayer. A product may be a circulating article by itself, or may be apart used in one portion of a circulating article. The silica coatingplating of the present invention may be formed throughout a product, ormay be formed on one portion of a product.

In one embodiment, a product is a product for outdoors. A product foroutdoors is generally used in an environment harsher than a product usedindoors, and is easy to be deformed/degenerated. In one embodiment, aproduct is a product for vehicles. In one embodiment, a product is anelectronic product (for example, for households). In one embodiment, aproduct is a product for automobiles. In one embodiment, a product is aproduct for decoration and/or for operation of a vehicle (for example,automobile). A product for decoration and/or for operation has manychances of bearing physical burden and is likely to be deformed. Since aluxurious appearance is preferred in a product (especially a product fordecoration and/or for operation) for a vehicle (for example,automobile), impartment of fingerprint resistance to a coating layersurface and maintenance of shine or metal gloss of a metal plating isdesirable. When a substrate is made of resin, the substrate is softerand easier to deform than a substrate made of metal. Thus, deformationof a substrate easily cause a plating layer applied thereon and acoating layer on the plating layer to exfoliate/crack. In particular, aplating layer and coating layer are both hard and easy to causeexfoliation therebetween, and when exfoliation occurs between platinglayer-coating layer, the air that got in between these layers would formanother layer and may significantly impair the appearance of a platingcoating. However, the inventors unexpectedly discovered that thestrength of the binding force of a plating layer and a silica coatinglayer can reduce generation of such exfoliation/cracking. In addition,the inventors discovered that when a coating layer comprises an addedresin, generation of exfoliation/cracking can be further reduced.Although not wishing to be bound by any theory, it is considered thatthis is due to increased flexibility of a coating layer and due to theacquired ability of dealing with deformation of a substrate bycomprising an added resin in the coating layer. Resin with plating isoften used in an electrical product for households, and since thecoating plating of the present invention can provide electricalresistance/insulation, physicochemical resistance, corrosion resistance,fingerprint resistance and the like, the coating plating can also besuitably used in such a house electrical product (for example, majorappliance, cell phone, digital camera, PC, beauty electrical product, orthe like). While a plating applied thereon a coating film does notgenerate a cool feel like a plastic when touched, the plated product ofthe present invention with silica coating can generate a metallic coolfeel when touched, which is an excellent point of the present invention.

The thickness of the coating layer of the present invention can be 0.01to 100 μm, or 0.05 to 100 μm, preferably can be 0.05 to 20 μm, 0.05 to15 μm, 0.1 to 20 μm, or 0.1 to 15 μm, more preferably 0.1 to 10 μm,further preferably can be 0.1 to 5 μm, and in one embodiment, can be 1to 20 μm, 1 to 15 μm, 1 to 10 μm, 2 to 7 μm, or 3 to 5 μm, and a coatinglayer with such range of thicknesses can provide strength that issufficient for protection of a substrate and a plating layer.Furthermore, in such a case in which the thickness of a coating layeris, for example, more than 0.1 μm, more than 0.2 μm, more than 0.3 μm,more than 0.4 μm, or more than 0.5 μm, protection effect by the coatingcan be powerful, and especially when the thickness of a coating layer is0.5 μm or more, the thickness can be sufficient for various purposes(for example, impartment of electrical resistance/insulation, impairmentof resistance against physicochemical change or damage, impairment ofcorrosion resistance, and the like). In addition, since the thickness ofthe coating layer of the present invention is thicker than an extremelythin layer (for example, less than 0.1 μm) such as a fluorine coating,there is a concern of causing a crack (for example, a crack can occur bycontraction upon curing a coating agent or the like), but it wasconfirmed that generation of a crack is hardly observed with theabove-described range of suitable thicknesses. In addition, thethickness of a coating layer can affect the appearance of a coatedarticle. When a coating layer is thin (for example, about 0.1 to 1 μm),the texture of a plating layer would hardly be impaired, but especiallywhen the thickness of the coating layer is 5 μm or less, the metal feelcan be maintained in the appearance unlike a general coated part.

Dye and/or pigment may be added to the coating layer of a product forsupplemental coloring of a plating layer. The strength of thesupplemental coloring effect may change depending on the thickness of acoating layer. Especially a plated product for automobiles is oftenrequired to focus on the design and make fine adjustment of color tone.Since the silica coating of the present invention is hard, sufficientphysiochemical protection can be obtained even with thin coating layerand a coating layer being thin enables fine adjustment of the color toneof a plating layer, and thus the silica-coated plated substrate of thepresent invention can be especially useful for a part for automobiles.The thickness of the coating layer of the present invention can be 0.01to 100 μm, or 0.05 to 100 μm, preferably can be 0.05 to 20 μm, 0.05 to15 μm, 0.1 to 20 μm, or 0.1 to 15 μm, more preferably 0.1 to 10 μm,further preferably can be 0.1 to 5 μm, and in one embodiment, can be 1to 20 μm, 1 to 15 μm, 1 to 10 μm, 2 to 7 μm, or 3 to 5 μm, wherein thecoating layer of such range of thicknesses can obtain supplementalcoloring effect that is sufficient for a plating layer. Furthermore, insuch a case wherein the thickness of a coating layer is, for example,0.1 μm or more, 0.2 μm or more, 0.3 μm or more, 0.4 μm or more, or 0.5μm or more, the supplemental coloring effect by the coating layer can beexerted even more strongly, and especially a coating layer of thethickness of 0.1 μm or more can be sufficient for expression of a widerange of color tones, but even when a coating layer with such thicknessis applied, the coating layer of the present invention can enablecoloring while still maintaining the texture/color tone of a platinglayer.

(Fingerprint Resistance)

The effect of suppressing impartment of a fingerprint of a coating layer(fingerprint resistance) can be evaluated by measuring the contact angleof the staining substance of a fingerprint to a coating layer. Thelarger the contact angle, the more excellent the fingerprint resistanceis.

The “contact angle” used in the preset specification is an angle made bya liquid surface and a solid surface at a place wherein a free surfaceof a static liquid contacts a solid wall. The contact angle used in thepresent specification is a value measured with the θ/2 method.

Upon measurement, it is possible to use oleic acid which is the maincomponent of the stain of a fingerprint as a measurement liquid thatbecomes a substitution for the stain of a fingerprint. In the presentspecification, “having fingerprint resistance” refers to a contact angleof when oleic acid is used being 60° or more.

In the silica-coated product of the present invention, the contact angle(oleic acid) is 65° or more, especially preferably 68 to 80°.

In addition, when water is used, good fingerprint resistance is achievedif the contact angle is 90° or more. In the silica-coated product of thepresent invention, the contact angle (water) is 100° or more, especiallypreferably 105 to 120°.

(Fingerprint Wipe Off Ability)

In the present invention, “fingerprint wiping ability” is an indicatorof the likeliness of a fingerprint remaining on a target surface of whenfingerprints is wiped off with a nonwoven fabric gauze after passing 5or more days since imparting a fingerprint on the target surface.

When a fingerprint remaining on a surface A after wiping off thefingerprint with a nonwoven fabric gauze after passing 5 or more dayssince imparting the fingerprint to the surface A is less than afingerprint on a surface B after wiping off the fingerprint with anonwoven fabric gauze in the same manner after passing the same timeperiod since imparting the fingerprint on the surface B in the samemanner, the surface A has an enhanced fingerprint wipe off ability thanthe surface B.

The silica-coated product of the present invention has an enhanced andsignificantly excellent fingerprint wipe off ability compared to aproduct that is not silica-coated. Thus, even when a fingerprint isimparted, the silica-coated product of the present invention can readilywipe off the fingerprint.

(Metal Gloss)

In one embodiment, since a coating layer formed on the surface of aplating layer is thin, an uneven state in a substrate surface and theplating layer will not be changed by the coating layer and the shineand/or gloss of the plating layer will not be impaired by the coatinglayer.

In view of the above, it is possible to provide a coated plated productwhile maintaining the appearance and design intended to be expressed bythe unevenness of a substrate surface.

The metal gloss of the plated product of the present invention can beevaluated by measuring the glossiness of the product surface. Theglossiness in the present invention is defined by the following formula.

Glossiness=2−log₁₀ (reflection factor)

Reflection factor=Reflection light amount/Incident light amount

For the measurement of the glossiness, for example, the DensitometerND11 manufactured by NIPPON DENSHOKU INDUSTRIES Co., LTD ca be used.

In the present invention, changing percentage (%) of glossiness is shownby the following formula:

(Glossiness after impartment of coating−glossiness before impartment ofcoating)/glossiness before impartment of coating×100

In the silica-coated product of the present invention, the changingpercentage of the glossiness is within the range of 30% (−30% to 30%),more preferably within the range of 10% (−10% to 10%), especiallypreferably within the range of 5% (−5% to 5%).

(Hardness)

The hardness of a substrate, plating layer and silica-coating layer canbe measured with the JIS K5600-5-4 scratch hardness (pencil method).

(Adhesion Force)

The adhesion force between a substrate and a plating layer and theadhesion force between a plating layer and a silica-coating layer can bemeasured with the JIS K5600-5-6 attachment ability (crosscut method).

In the present specification, “or” is used when “at least 1 or more” ofthe matters listed in the sentence can be employed. The same applies to“or”. When the present specification explicitly describes “within therange” of “two values”, the range includes the two values.

Reference documents cited in the present specification, such as sciencedocuments, patents, and patent applications, are incorporated herein byreference in their entirety to an extent that each of which isspecifically described.

(Other Embodiments)

As discussed above, the present invention has been explained whileshowing an embodiment preferable for easy understanding. While thepresent invention is explained below based on the Examples, theabove-discussed explanation and the Examples below are provided only forthe purpose of exemplification and not provided for the purpose oflimiting the present invention. Therefore, the scope of the presentinvention is not limited by the embodiments and Examples specificallydescribed in the present specification, but only limited by the Claims.

EXAMPLES

The present invention is further specifically explained by the followingExamples. However, the present invention is not limited by the followingExamples.

A. Evaluation Method of Fingerprint Resistance

The evaluation of the fingerprint resistance was carried out bymeasuring a contact angle. The measurement of the contact angle wascarried out by using a contact angle meter (manufactured by KYOWAINTERFACE SCIENCE CO., LTD.) to drop a measurement liquid to the surfaceof a product and measure the contact angle. The targeted measurementliquid was set to be oleic acid which is the main component of the stainof a fingerprint. In addition, a contact angle of when water is used asmeasurement liquid was also measured.

Furthermore, oleic acid was used to attach a fingerprint to the surfaceof the product and visual observation was carried out, whereinevaluation was carried out with the following criterion as well.

(Evaluation of Fingerprint Resistance)

⊚ Excellent: Attachment of fingerprint not noticed at all.

○ Good: Attachment of fingerprint hardly noticed.

x Inferior: Attachment of fingerprint noticeable.

B. Measurement of membrane thickness of coating layer The membranethickness of the coating layer was measured with a contact-type membranethickness measurement apparatus (automatic contact angle meter DM-301manufactured by KYOWA INTERFACE SCIENCE CO., LTD.).

C. Measurement of Glossiness

Glossiness was measured using the Densitometer ND11 manufactured byNIPPON DENSHOKU INDUSTRIES Co., LTD.

The measurement of the glossiness was carried out twice, before applyinga coating agent to the surface of the plating layer and afterapplication and formation of the coating layer, and the values ofglossiness were compared.

D. Hardness Evaluation Method

The evaluation of hardness was carried out with the JIS K5600-5-4scratch hardness (pencil method).

E. Adhesion Force Evaluation Method

The evaluation of the adhesion force was carried out with the JISK5600-5-6 attachment ability (crosscut method).

Example 1

(1) ABS Resin is Used and a Part Made of Synthesized Resin was Molded byInjection Molding.

The surface of the obtained part was a smooth surface and the arithmeticaverage surface roughness was 0.03 μm.

(2) Etching Step of the Part Made of Synthesized Resin

This part made of synthesized resin was immersed for about 10 minutes inan etching liquid of about 65° C. having the following composition tocarry out the etching of the surface of the part.

<Etching Liquid Composition>

Chromic acid about 400 g/dm³

Sulfuric acid about 400 g/dm³

(3) Catalyst Step of the Part Made of Synthesized Resin

Next, the part made of synthesized resin was immersed for two minutes ina catalyst liquid of about 35° C. having the following composition andfurther immersed for three minutes in an accelerator liquid of 40° C. tocause palladium as a metal catalyst nucleus to attach on the roughenedsurface thereof.

<Catalyst Liquid Composition>

Palladium chloride about 0.1 g/dm³

Stannous chloride about 10 g/dm³

Hydrochloric acid about 250 dm³/dm³

(4) Electroless Metal Plating Step

Next, the electroless nickel plating bath (30° C.) shown below was usedto form a nickel plating layer with the thickness of about 0.2 μm.

<Electroless Nickel Plating Composition>

Nickel sulfate about 20 g/dm³

Sodium phosphinate about 10 g/dm³

Citrate about 30 g/dm³

(5) Step of Forming Electroplating Layer

Next, the part was sequentially immersed in the electroplating liquidsof the following compositions (a) to (c) to form three layers ofelectroplating layers to the surface of the electroless plating layer ofthe part surface.

<Composition of Electroplating Liquids>

(a) Nickel plating

Nickel sulfate 280 g/dm³

Nickel chloride 50 g/dm³

Boric acid 30 g/dm³

(b) Copper plating

Copper sulfate 200 g/dm³

Sulfuric acid 80 g/dm³

Gloss agent Suitable amount

(c) Chrome plating

Trivalent chrome plating liquid

Envirochrome, Twilight Chrome (manufactured by MACDERMID PERFORMANCESOLUTIONS JAPAN K.K.), Top Finechrome (manufactured by OKUNO CHEMICALINDUSTRIES), or the like.

(6) Next, a coating agent was applied to the surface of the platinglayer formed in such a manner and a coating layer was formed by carryingout curing treatment at 80° C. to obtain a plated product. This coatingagent comprised 10 wt % of tetraethoxysilane (silica compound), 20 wt %of acrylic resin (added resin), 5 wt % of titanium diisopropoxybisacetylacetonate (organic metal compound) and 65 wt % of1-ethoxy-2-propanol (solvent). The membrane thickness of the coatinglayer was 4 μm which was measured by the contact-type membrane thicknessmeasurement apparatus. The hardness of the coating layer was 3H whichwas measured by the JIS K5600-5-4 scratch hardness (pencil method), andthe adhesion force of the coating layer was class 0 which was measuredby the JIS K5600-5-6 attachment ability (crosscut method).

The coating layer was excellent in fingerprint resistance and was notimpaired in terms of the texture and aesthetic of the plating layer.

It was found that the coating layer is hard and can prevent physicaldamage of the plated product. In addition, the coating layer wasstrongly adhered to the plating layer, being stable without exfoliationor cracking.

Example 2

Other than the point that a coating agent further comprises an organicpigment of 0.01 wt % of copper phthalocyanine, a plated product wasprepared in the same manner as Example 1. The hardness of the coatinglayer was 3H which was measured by the JIS K5600-5-4 scratch hardness(pencil method), and the adhesion force of the coating layer was class 0which was measured by the JIS K5600-5-6 attachment ability (crosscutmethod).

While supplemental coloring effect of blue color in addition to silvercolor of the chrome plating was clearly observed in the plated productobtained in this Example, the plated product exhibited texture and finesight of the chrome plating which are similar to the plated productobtained in Example 1.

Therefore, the plated product of the present invention is excellent infingerprint resistance, physical resistance and stability, and can alsomaintain the texture and aesthetic of the plating layer. Furthermore,fine adjustment of color tone can be made while still maintaining theluxurious feel of the plating by carrying out supplemental coloringwithout impairing the texture and aesthetic of the plating layer.

(Note)

As disclosed above, the present invention is exemplified with itspreferred embodiments. However, it is understood that the scope of thepresent invention should be interpreted solely based on the Claims. Itis also understood that any patent, any patent application, and anyreferences cited herein should be incorporated herein by reference inthe same manner as the contents are specifically described herein.

INDUSTRIAL APPLICABILITY

The plated product of the present invention is suitable for anelectronic product (especially for households), a member for decoration,an interior member of an automobile such as a lock release lever or anoperation knob of an automobile, exterior member, and the like.

1. A plated product comprising: a substrate made of resin; a platinglayer formed on a surface of the substrate; and a coating layercomprising a silica compound, which is formed on a surface of theplating layer.
 2. The plated product of claim 1, wherein a thickness ofthe coating layer is 0.1 to 20 μm.
 3. The plated product of claim 1,wherein a thickness of the coating layer is 0.1 to 10 μm.
 4. The platedproduct of claim 1, wherein a thickness of the coating layer is 0.1 to 5μm.
 5. The plated product of claim 1, wherein the coating layercomprises at least one of a dye and a pigment.
 6. The plated product ofclaim 1, wherein the coating layer comprises an added resin.
 7. Theplated product of claim 1, which is for a vehicle.
 8. A method ofmanufacturing a plated product comprising a step of forming a platinglayer on a surface of a substrate made of resin; and a step of applyinga coating agent comprising a silica compound to a surface of the platinglayer to form a coating layer.
 9. A method of manufacturing of claim 8,comprising a step of carrying out plasma treatment, acid treatment, oralkali treatment to a formed plating layer before the step of forming acoating layer.
 10. The method of manufacturing of claim 8, wherein athickness of the coating layer is 0.1 to 20 μm.
 11. The method ofmanufacturing of claim 8, wherein a thickness of the coating layer is0.1 to 10 μm.
 12. The method of manufacturing of claim 8, wherein athickness of the coating layer is 0.1 to 5 μm.
 13. The methodmanufacturing of claim 8, wherein the coating agent comprises an addedresin.
 14. The method of manufacturing of claim 8, wherein the productis a product for a vehicle or an electronic product for a household.